Puerto Rico Adventures, Arecibo

Puerto Rico’s Porta Atlántico stretches west from Dorado to Camuy, 63 miles from San Juan. The region’s northern coastline and inland forests and farms lure adventurers with cave explorations as well as the chance to see the world’s largest single dish radio telescope at Arecibo.

In the Rio Camuy Cave Park (Parque de las Cavernas del Rio Camuy), an orange tram takes us along a winding road that descends a ravine lush with ferns, ficus and shrubs. Along the hillsides thick tree roots dangle in the air. Thinner clumps rim the cave’s entrance like otherworldly eyelashes.

From here we walk into the main cavern, where the temperature hovers around 65-F and the interior is less dim that most movie theaters. Some natural light illuminates the space plus the formations are lit. The light plus the fact that the path, although slippery in places, is relatively easy to walk make this underground experience a good first cavern tour for young kids.

Although the guide dutifully points out the thick stalagmites and long stalactites, what’s more impressive than the formations is the cavern’s size. The ceiling in the main chamber, Cueva Clara, rises 173-feet, enough the guide tells us to stand a 17-storey building inside. At an opening, we look down to see the muddy river 400-feet below.

At another point the path narrows through tall rocks and the guide asks us to find La Bruja, the witch. From here on remember NOT to touch the hand railing. The wickedly, water carved rock won’t bother you, but the bat guano caking the rail will. Hundreds of bats literally hang out here, turning the air acrid and warming it slightly with their body heat.

The cavern’s bigness and its bats make the park led tour enough of an adventure for some. For those age 15 and older who want more thrills, sign-on with Aventuras Tierro Adentro to explore Angels Cave, another in the large Rio Camuy system. Their outing involves gliding through the cave on zip lines and rappelling 250 feet.

Not far from the Rio Camuy Cave Park is the Arecibo Observatory, the world’s
largest single dish radio telescope. The dish or reflector, 1000 feet in diameter, sits atop a sinkhole. Suspended 450-feet above the dish is a 900-ton platform arm with a dome that collects the energy.

It’s an impressive site. If the telescope looks familiar that’s because it starred in the climactic scenes in the James Bond movie Goldeneye. The telescope is employed, as engineer Dana Whitlow, says ”to learn about the motion of masses of hydrogen in space.” That may include other galaxies as well as extraterrestrial life.

Scientists discovered the first binary pulsar, a spinning neutron star that emits beams of radiation, at Arecibo, a find that confirmed Einstein’s theory of relativity and led to winning the 1974 Nobel Prize in physics. The hands-on exhibits in the Visitor Center explain aspects of astronomy and atmospheric science.

Hungry? Skip the hot dog and soda offerings at the observatory and head to the oceanfront town of Islote, part of Arecibo. Salitre Meson Costero serves fresh seafood. Their back patio fronts the Atlantic. Dine on local snapper and lobster as well as island specialties such as yucca fries and plantains as you listen to the surf and ponder the day’s mysteries.